An Impossibly 'Funny' Book on Physics

By Gary Schmidgall

From spacewalks to time travel: Physicist and futurist Michio Kaku says time travel to the future, not the past, "is possible" in principle.

Well into the newest of Michio Kaku's several layperson-friendly books, Physics of the Impossible (Doubleday), one encounters as an epigraph this observation by the prolific sci-fi writer and biochemist Isaac Asimov: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka' (I found it!) but 'That's funny.'"

Which—this will certainly date me!—recalled to mind "Time for Beany." Whenever this '50s TV puppet started to tell a funny story, his loyal sidekick, Cecil the seasick sea serpent, would ask, "Is this story funny ha-ha or funny peculiar?" Asimov obviously had the latter in mind, and boy-oh-boy has Kaku produced a "funny" book in that sense. Not a single one of his 15 chapters fails to leave one scratching the head and muttering, "That's funny." As in weird, Twilight Zone-ish, or plain absurd.

But beware: The very first of many provocative chapter epigraphs in Physics of the Impossible is Albert Einstein's remark, "If at first an idea does not sound absurd, then there is no hope for it." (There's one epigraphic slip: not Shakespeare but Neil Gaiman said "It is a fool's prerogative to utter truths that no one else will speak.") Kaku, a professor of theoretical physics at the Graduate Center and City College, is a consummate and multidisciplinary futurist, seemingly at home rubbing shoulders with the world's leading-edge physicists, mathematicians, astronomers, cosmologists and engineers. As the cofounder of string theory, which Kaku proudly calls "the leading (and only) candidate for a theory of everything," his credentials as a futurist are impeccable. His book is bound to leave a stodgy pastist like me with jaw dropped and mind boggled. But, though sometimes a term of art slips by unexplained (what's an accretion disk?), Kaku clearly has the knack for fooling the lay reader into thinking he can grasp at least the outline of the topics he explores. He also is careful to set these topics in historical and cultural contexts, aerating his discussions with cameo appearances by major scientific figures, suggestive tie-ins to the giants of science fiction, and fascinating parallels to world literature.

The purpose of this book "is to consider what technologies are considered 'impossible' today that might well become commonplace decades to centuries down the road." Late in the book, after discussing various notions of parallel universes, Kaku says, "As far-fetched as some of these ideas appear, they have been seriously considered by physicists." That statement applies to the entire book.

Kaku divides his impossibilities into three classes. Two-thirds of his book is devoted to 10 Class I technologies that are impossible today but "do not violate the known laws of physics." Achieving these "might be possible in this century, or perhaps the next, in modified form." Among these is the exploitation of those magnetic force fields so familiar to Trekkies. Maglev trains are already in their third decade, but Kaku says the great challenge is currently to develop a room-temperature superconductor (now it's necessary to cool one down to near absolute zero to reduce electrical resistance).

Another chapter is devoted to the practicalities of the "invisibility cloak" ubiquitous in SF, most recently in Harry Potter. This involves Kaku in a discussion of the work of the great Scottish physicist James Clerk Maxwell and of the fact that invisibility arises at the atomic level. What is needed here are "metamaterials" that "bend" light, and Kaku says that "in the last few years, metamaterials have actually been manufactured in the laboratory, forcing reluctant physicists to rewrite all the textbooks in optics." Within the next few decades or in this century, "a form of invisibility may become commonplace."

Can weapons be created that could destroy an entire planet, as in "Star Wars"? In a chapter on "Phasers and Death Stars" Kaku answers in the affirmative. In a chapter on teleportation (instant travel by a person or object from point A to point B), Kaku notes that it was invented by Gene Roddenberry for "Star Trek" because the Paramount Studio budget did not allow for costly simulation of rocket ships taking off and landing. But Kaku's serious discussion focuses on quantum theory, where "all the basic laws of common sense are violated: electrons can disappear and reappear elsewhere and electrons can be many places at the same time." Soon one is hearing about breakthrough research from just last year on one of the coldest substances in the universe, a Bose Einstein condensate or BEC, a millionth to a billionth of a degree above absolute zero (about minus 460 degrees Fahrenheit). Then Kaku ties teleportation to the development of quantum computers, which he predicts will make PCs on our desks obsolete.

Another Class I impossibility is telepathy, which has been bruited about since "mental telepathy" was coined in 1882. As with several Class I impossibilities, the Pentagon and our spook agencies have sunk lots of money into research. Between 1972 and 1995 the CIA paid psychics, remote viewers and researchers at the Stanford Research Institute $20 million. The results, Kaku reports, were worthless, but he is more bullish on mind-reading, in particular MRI-based lie detection.

The chapter on psychokinesis, after quickly disposing of spoon-bending nonsense, gets into the fascinating interface of mind and machine. Indeed, the future seems to have arrived earlier this summer. Kaku writes, "it is well within the laws of physics for a person in the future to be trained to mentally manipulate an electronic sensing device." Didn't The New York Times carry a story in May 2008 about monkeys trained to operate a prosthetic arm mentally through an embedded chip and biofeedback?

Other Class I chapters are devoted to robots and artificial intelligence, extraterrestrials and UFOs, antimatter and anti-universes, and starships (needed for escape from an Earth dying "in flames as it is consumed by the sun"—the good news being we have five billion years of lead-time to build our ark). This last chapter was probably hardest on my poor soft-sciences brain. "Are any reversed anti-universes possible?" Kaku asks at one point. I take his answer (yes) on faith.

Next come the Class II impossibilities, which Kaku defines as "technologies that sit at the very edge of our understanding of the physical world. If they are possible at all, they might be realized on a scale of millennia to millions of years in the future." There are three of these. The first opens the possibility of crashing through the universe's maximum speed limit, the speed of light, and traveling even faster. This notion, so delectable to SF writers, is viewed by Kaku as a sine qua non for travel to distant galaxies. Exploring it involves such theoretical exotica as the Alcubierre drive, negative energy, wormholes, black holes, and Planck energy.

The next Class II impossibility is time travel. Kaku rules it out to the past, but that to the future "is possible" in principle. He notes that, because clocks beat a bit slower in space, Russian cosmonaut Sergei Avdeyev, who orbited for 748 days, holds the world record for time travel. He "was hurled .02 seconds into the future." Quoting e. e. cummings—"there's a hell of a good universe next door; let's go"—Kaku addresses the third Class II notion: parallel universes. He cites the TV series "Sliders," in which a boy reads a book and is inspired to build a machine for "sliding" between universes. The book in question? Kaku's highly praised 1994 Hyperspace. (Among his other titles are Einstein's "Cosmos and Visions: How Science Will Revolutionize the 21st Century and Beyond.")

Last come the Class III impossibilities. These are technologies that violate the known laws of physics." If they turn out to be possible, they would "represent a fundamental shift in our understanding of physics." The first is perpetual motion machines, for centuries a rich source for charlatans and hoaxers, and the second is precognition or predictions of the future, which evokes one of Kaku's few bearish conclusions. If it turns out to be possible, it "would set off a major shake-up in the very foundation of modern physics."

Kaku refines his taxonomy for the no-way-José's of physics by suggesting what kinds of civiliza­tions will achieve these technologies. Corresponding to the classes of impossibilities, they are: the Type I civilization, which harvests all energy available on a given planet; Type II civilization, which can exploit the entire power of a sun, making it 10 billion times more powerful than Type I (Star Trek's Fed­eration of Planets is a Type II); Type III civilization, able to utilize the power of an entire galaxy, another 10 billion times more powerful than II (the Empire in "Star Wars" and civilization in Asimov's Foundation series are Type III).

Where do we fit in? In Hyperspace, Kaku defined us on Earth as a Type 0 civilization: "we use dead plants, oil and coal to fuel our machines" and we "use only a fraction of the sun's energy that falls on our planet." A Type 0 civilization is "still wracked with sectarianism, fundamentalism, and racism"— though Kaku sees glimmers of a unified planetary culture that Type I requires in the European Union and in the ascendance of English as the global language. Kaku envisages a planetary culture that will "perhaps be dominated by youth culture and commercialism." This could be the only bit of old news in the whole book.

Kaku guesses that in a couple of hundred years we might hoist ourselves to Type I status. That is, of course, assuming we don't (to use some physics jargon) become decoherent. That is, if either by accident or intention we blast ourselves to smithereens in a nuclear holocaust.

As Kaku ominously notes, "Perhaps the one reason that we don't see Type I civilizations in the galaxy is because they never made the transition, i.e. they self-destructed."

My space has run out, and I haven't even mentioned Kaku's talk of diamagnets, nanobots, gamma ray bursters, charge parity-reversed universes, tachyons, or NASA's Laser Interferometer Space Antenna. Scheduled for launch in 2015 and involving 3 million-mile-long laser beams, LISA will be the largest scientific instrument of all time.